1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method, and a program. More in detail, the present invention relates to an image processing apparatus, an image processing method, and a program which receive, through a network, images photographed by a plurality of cameras for photographing images to be applied to three-dimensional (3D: 3-Dimensional) image display and display the received images on a display unit.
2. Description of the Related Art
In recent years, systems for displaying a three-dimensional image, i.e., a 3D (3-Dimensional) image have been actively developed and used. Representative systems for displaying the 3D image include the passive stereo system and the active stereo system.
The passive stereo system allows the passage of only light vibrating in a particular direction by using a polarizing filter, for example, to separately produce the image for the left eye and the image for the right eye to be observed by the left eye and the right eye of an observer, respectively. Before the output light forming an image displayed by an image display device reaches the eyes of the observer, the light is separated into the light for the left eye and the light for the right eye through the polarizing filter. For example, through polarizing glasses worn by the observer, the image light for the left eye is input only to the left eye without being input to the right eye, and the image light for the right eye is input only to the right eye without being input to the left eye. In this manner, the system inputs the image for the left eye and the image for the right eye to the left eye and the right eye of the observer, respectively, to thereby achieve stereoscopic vision.
Meanwhile, the active stereo system is called a time-division system, for example, and achieves the separation into the left image and the right image by using shutter glasses in synchronization with the frame switching timing of the image display device. According to the mechanism of the system, the image display device displays the image for the left eye and the image for the right eye by switching between the images in each frame, and the shutter glasses worn by the observer cover the right eye of the observer during the display of the image for the left eye and cover the left eye of the observer during the display of the image for the right eye.
To display the 3D image in accordance with the systems as described above, images photographed from a plurality of different viewpoints are used. For example, the images photographed by a camera L for photographing the image for the left eye and a camera R for photographing the image for the right eye are used.
For example, when the images photographed by the two cameras L and R are transferred through a network and received and displayed by an image processing apparatus, such as a PC (Personal Computer) and a TV (Television), located at a remote location, a process is performed which generates display data by reliably receiving the two images photographed at the same time by the cameras L and R. Systems of this type are described in the publications of Japanese Unexamined Patent Application Publication Nos. 2005-94073 and 2006-140618, and Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 11-504167, for example.
However, it is difficult to completely prevent the loss and delay of a data transfer packet in network communication. For example, there arises such a situation that the image photographed by the camera L at a time t1 has been received but the image photographed by the camera R at the same time t1 has not been received. In this case, the apparatus having received the data fails to display a correct 3D image.
For example, if the apparatus which receives and displays data has received the images photographed by the camera L at times t, t+1, and so forth, but has received only the images photographed by the camera R at times up to a time t−1, the image display is stopped with the images photographed at the time t−1.
Alternatively, a process may be performed which displays the correct images photographed by the camera L in accordance with the time transition of the times t, t+1, and so forth, while continuing to display the image photographed by the camera R at the time t−1. However, the process of displaying asynchronous images, such as the L image (image for the left eye) and R image (image for the right eye) as described above, impairs the correct stereoscopic effect of the 3D image.